The families of 14 servicemen were yesterday grieving for their loved ones and wondering what mechanical fault could have brought down the Nimrod in which they were flying. Attention focused on RAF Kinloss in north-west Scotland, where 12 of the dead, all members of the 120 Squadron, were based.

The squadron leader, Wing Commander Martin Cannard, led the tributes, saying: "They were hard-working guys doing important jobs which they were committed to, which they enjoyed. They were professional, cheerful and positive in everything they did."

Also on board the Nimrod MR2, which crashed near Kandahar, were Lance Corporal Oliver Simon Dicketts, of the Parachute Regiment, and Joseph David Windall, of the Royal Marines.

Senior officers, trained military counsellors and colleagues of those who died spent the day comforting families at Kinloss. Floral tributes were placed at the gates to mark the biggest single loss of British troops since the Falklands war.

The station commander, Group Captain Chris Birks, said: "All were long-serving and experienced air crew and were known to me personally. The station is in mourning." Group Capt Birks said his priority was to provide support to the families of those lost.

Flags flew at half mast at the base while local people left messages at the guardhouse. A candle was placed on one of the base's walls, surrounded by sunflowers and a stone with the saltire painted on it.

The base chaplain, Father Ivan Boyle, said it was the "blackest day" he had known at Kinloss. "Everyone is struggling, everyone is dealing with this thing in different ways," he said. "Death is part of our business. But no one wants it or looks for it and it still comes as a shock. I think at the moment people have questions."

There were concerns on the base about what went wrong on the Nimrod. The planes did not fly yesterday and checks were carried out on them, but Group Capt Birks insisted they would fly if needed.

The community is particularly close because the base is the only home of the Nimrods, which means that service personnel spend lengthy tours in Kinloss. They are proud of the history of 120 Squadron - motto "Endurance" - which flew B-24 Liberators on anti U-boat patrols over the Atlantic in the second world war, and more recently served in the Falklands and Gulf wars.

Outside the base, members of the civilian community paid tribute, with a junior football team holding a minute's silence before its game yesterday afternoon. Andrew Gittings, owner of Seapark filling station near the base, said: "We can't understand how such a sophisticated aircraft could just simply fall from the sky."

Tony Blair said: "This tragedy will distress the whole country and our thoughts go out immediately to the families of those who have died. British forces are engaged in a vital mission in Afghanistan. This terrible event starkly reminds us of the risk that they face daily." The accident was the subject of prayers at yesterday's morning service at Crathie Kirk, near Balmoral Castle, which was attended by the Queen and the prime minister.

The Rt Rev Alan McDonald, moderator of the general assembly of the Church of Scotland, asked a member of the congregation to light a candle to help people remember the 14 servicemen who died. He also asked that God give leaders such as the prime minister "wisdom to make decisions".